1. Field of the Invention
The present invention relates to a method for processing cloth to form a three-dimensional design pattern on the cloth.
2. Related Art
At present, cloth of high functionality has been developed, finding wide application in the fields of automotive upholstery and building material.
Among such cloth of high functionality is one with three-dimensional design patterns formed on its surface to make it appear solid and refined, which has attracted attention from various industrial fields, especially for use as automotive seat and wall covering material.
Certain techniques are already known for processing cloth to form three-dimensional design patterns on it, which are generally classified into two groups depending on whether they are based on physical or chemical means.
Such prior techniques based on physical means that are applied to a commonly printed cloth include methods wherein the cloth is passed between engraved rolls heated to a high temperature under pressure to form three-dimensional design patterns on the cloth (such as embossing and schreiner calendering). These methods, however, have the disadvantages of involving passage of cloth between heated rolls under a high pressure, which causes the cloth to become hardened and flattened to a significant extent, as well as to assume a metallic luster caused by the heated rolls with a possible change in its color due to the roll heat.
Such prior techniques based on chemical means include a method wherein cloth is printed with a color paste containing chemicals acting to shrink the fiber of the cloth or reduce its weight, thereby forming three-dimensional design patterns on it, as disclosed in JP-B-47-23709.
This method, however, has the disadvantage of requiring naphthol derivatives, hardly soluble in water, to be directly applied to a cloth, resulting in uneven application of the color paste to the cloth, which causes the method to involve a problem with the reproducibility of the resultant three-dimensional design patterns on the cloth.
In the meantime, an ink-jet system has attracted attention as a method for applying inks containing fiber-shrinking agents to a cloth to form a three-dimensional design pattern on the cloth.
This ink-jet system-based method is advantageous in that it allows inks in small amounts to be injected onto a cloth by varying the amounts of the inks and their positions to a subtle extent, thereby providing the cloth with fine three-dimensional design patterns.
Among such methods using an ink-jet system to form a three-dimensional design pattern on cloth is one in which inks containing fiber-shrinking agents are injected from nozzles onto a pile fabric to shrink the piles, thereby forming three-dimensional design patterns on the fabric.
This method, however, has the disadvantage of involving the use of inks with a high viscosity of 100 to 200 cps to prevent ink penetration through the cloth that may otherwise occur, thereby not allowing use of a widespread conventional ink-jet printer for inks of low-viscosity type (1 to 10 cps), but requiring new arrangements with an ink-jet printer optionally designed for high-viscosity inks.
In addition, this method is disadvantageous in that the use of such high-viscosity inks, combined with fiber-shrinking agents that are, as a general rule, hardly soluble in water and thus difficult to disperse in the inks, causes the ink-jet printer to be subject to nozzle clogging and other similar trouble.
A further disadvantage of this method, due to its necessity for the use of such high-viscosity inks, is failure of the fiber-shrinking agents contained in the inks to penetrate deep inside a cloth, resulting in poor development of the resultant three-dimensional design patterns on the cloth.
It is therefore an object of the present invention to provide a method for processing cloth to form excellent three-dimensional design patterns on the cloth not only by a conventional printing system, but also by an ink-jet system, while solving the problems of the conventional methods mentioned above, as well as to provide a cloth processed by such a method.
As a result of our efforts to solve the problems of the conventional methods mentioned above, we discovered a two-step process of applying a phenol derivative as a fiber-shrinking agent, hardly soluble in water, to a cloth, which consists of a first step of treating the cloth with a solution of the phenol derivative reacted with a hydroxide of an alkali metal or alkali-earth metal for conversion into its corresponding water-soluble salt to achieve uniform application of the fiber-shrinking agent to the cloth, and a second step of treating the cloth with a solution containing a chemical capable of converting the salt into its original phenol derivative to restore the fiber-shrinking agent applied in its water-soluble form to the cloth to its original function. This discovery led us to accomplish the present invention.
Specifically, the present invention consists in
(1) a method for processing cloth to form a three-dimensional design pattern on the cloth, comprising two processesxe2x80x94process (a) wherein it is treated with solution A containing a salt formed from a derivative of phenol and a hydroxide of an alkali or alkali-earth metal, and process (b) wherein it is treated with solution B containing a chemical capable of restoring the salt in solution A to its original phenol derivative;
(2) a method as specified in (1) above, in which the chemical capable of restoring the salt in solution A to its original phenol derivative is selected from among three types of compoundsxe2x80x94a salt formed from an inorganic acid and a weak base, carboxylic acid and a salt formed from carboxylic acid and a weak base;
(3) a method as specified in (1) above, in which cloth is subjected to said process (a) and process (b) in that order before process (c) of applying dyes to the cloth for its printing;
(4) a method as specified in (1) above, in which cloth is subjected to said process (b) and process (a) in that order before process (c) of applying dyes to the cloth for its printing;
(5) a method as specified in any of (1) to (4) above, in which said process (a) and process (b) are based on an ink-jet system;
(6) a method as specified in (3) or (4) above, in which said process (c) is based on an ink-jet system;
(7) a method as specified in (6) above, in which cloth is treated with said solution A or B contained in an ink acceptor solution for its ink-jet printing; and
(8) a cloth processed by such a method as specified in any of (1) to (7) above to form three-dimensional design patterns on it.